
<script> 
/*
  Math.uuid.js (v1.4)
 http://www.broofa.com
 mailto:robert@broofa.com
   
 Copyright (c) 2010 Robert Kieffer
 Dual licensed under the MIT and GPL licenses.
 */
   
 /*
  * Generate a random uuid.
  *
  * USAGE: Math.uuid(length, radix)
  *   length - the desired number of characters
  *   radix  - the number of allowable values for each character.
  *
  * EXAMPLES:
  *   // No arguments  - returns RFC4122, version 4 ID
  *   >>> Math.uuid()
  *   "92329D39-6F5C-4520-ABFC-AAB64544E172"
  *
  *   // One argument - returns ID of the specified length
  *   >>> Math.uuid(15)     // 15 character ID (default base=62)
  *   "VcydxgltxrVZSTV"
  *
  *   // Two arguments - returns ID of the specified length, and radix. (Radix must be <= 62)
  *   >>> Math.uuid(8, 2)  // 8 character ID (base=2)
  *   "01001010"
  *   >>> Math.uuid(8, 10) // 8 character ID (base=10)
  *   "47473046"
  *   >>> Math.uuid(8, 16) // 8 character ID (base=16)
  *   "098F4D35"
  */
 (function() {
   // Private array of chars to use
   var CHARS = '0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz'.split('');
   
   Math.uuid = function (len, radix) {
     var chars = CHARS, uuid = [], i;
     radix = radix || chars.length;
   
     if (len) {
       // Compact form
       for (i = 0; i < len; i++) uuid[i] = chars[0 | Math.random()*radix];
     } else {
       // rfc4122, version 4 form
       var r;
   
       // rfc4122 requires these characters
       uuid[8] = uuid[13] = uuid[18] = uuid[23] = '-';
       uuid[14] = '4';
   
       // Fill in random data.  At i==19 set the high bits of clock sequence as
       // per rfc4122, sec. 4.1.5
       for (i = 0; i < 36; i++) {
         if (!uuid[i]) {
           r = 0 | Math.random()*16;
           uuid[i] = chars[(i == 19) ? (r & 0x3) | 0x8 : r];
         }
       }
     }
   
     return uuid.join('');
   };
   
   // A more performant, but slightly bulkier, RFC4122v4 solution.  We boost performance
   // by minimizing calls to random()
   Math.uuidFast = function() {
     var chars = CHARS, uuid = new Array(36), rnd=0, r;
     for (var i = 0; i < 36; i++) {
       if (i==8 || i==13 ||  i==18 || i==23) {
         uuid[i] = '-';
       } else if (i==14) {
         uuid[i] = '4';
       } else {
         if (rnd <= 0x02) rnd = 0x2000000 + (Math.random()*0x1000000)|0;
         r = rnd & 0xf;
         rnd = rnd >> 4;
         uuid[i] = chars[(i == 19) ? (r & 0x3) | 0x8 : r];
       }
     }
     return uuid.join('');
   };
   
   // A more compact, but less performant, RFC4122v4 solution:
   Math.uuidCompact = function() {
     return 'xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx'.replace(/[xy]/g, function(c) {
       var r = Math.random()*16|0, v = c == 'x' ? r : (r&0x3|0x8);
       return v.toString(16);
     });
   };
 })();
 
//调用方法：
alert(Math.uuid());
</script>